Monitoring of CO Binding Sites on Stepped Pt Single Crystal Electrodes in Alkaline Solutions by in Situ FTIR Spectroscopy
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Título: | Monitoring of CO Binding Sites on Stepped Pt Single Crystal Electrodes in Alkaline Solutions by in Situ FTIR Spectroscopy |
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Autor/es: | Farias, Manuel J.S. | Busó-Rogero, Carlos | Tanaka, Auro A. | Herrero, Enrique | Feliu, Juan M. |
Grupo/s de investigación o GITE: | Electroquímica de Superficies |
Centro, Departamento o Servicio: | Universidad de Alicante. Departamento de Química Física | Universidad de Alicante. Instituto Universitario de Electroquímica |
Palabras clave: | Electrocatalysis | Alkaline media | CO adsorption | Pt surface | Site-specific |
Área/s de conocimiento: | Química Física |
Fecha de publicación: | 17-dic-2019 |
Editor: | American Chemical Society |
Cita bibliográfica: | Langmuir. 2020, 36(3): 704-714. doi:10.1021/acs.langmuir.9b02928 |
Resumen: | The site geometry preference of CO binding on stepped Pt single crystals in alkaline solution was investigated by in situ FTIR spectroscopy. The surfaces of the Pt single crystals consisted of different width (111) terraces, interrupted by (110) or (100) monatomic steps. Experiments carried out with CO adsorbed exclusively on the top of the steps revealed that only linearly bonded CO formed on the (110) steps, while two CO binding geometries (linear and bridge) were observed on the (100) steps. On one hand, for CO adsorbed only on the steps, the positions of the bands corresponding to linearly bonded CO were similar, regardless of the density of steps, suggesting the existence of an interaction between COads only along the line of the steps. On the other hand, for full CO coverage, the CO stretching frequencies and the geometry of bound CO were sensitive to the width of the (111) terraces and the step orientations. Consequently, the CO binding sites favored linearly bonded CO for surfaces consisting of shorter (111) terraces and (110) steps. Bridge-bonded CO was favored on surfaces consisting of shorter (111) terraces interrupted by (100) steps. In order to understand the origin of the preference of CO binding sites, the results were compared to the corresponding behavior in acid media, which revealed that, in addition to the effect inherent to the Pt surface, the charge on the metal side in an aqueous environment should be taken into consideration. The analysis suggested that the CO adlayers formed at full coverage in acidic and alkaline media had different structures. On the other hand, the structure of the layer of CO adsorbed only at the steps was independent of pH. |
Patrocinador/es: | M.J.S.F. is grateful to PNPD/CAPES (Brazil). A.A.T. acknowledges CAPES (PROCAD-2013) and CNPq (309066/2013-1). J.M.F. and E.H. thank the MINECO (Spain) project-CTQ2013-44083-P. C.B.-R. also acknowledges Generalitat Valenciana (APOSTD/2017/010). |
URI: | http://hdl.handle.net/10045/102247 |
ISSN: | 0743-7463 (Print) | 1520-5827 (Online) |
DOI: | 10.1021/acs.langmuir.9b02928 |
Idioma: | eng |
Tipo: | info:eu-repo/semantics/article |
Derechos: | © 2019 American Chemical Society |
Revisión científica: | si |
Versión del editor: | https://doi.org/10.1021/acs.langmuir.9b02928 |
Aparece en las colecciones: | INV - EQSUP - Artículos de Revistas |
Archivos en este ítem:
Archivo | Descripción | Tamaño | Formato | |
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2020_Farias_etal_Langmuir_final.pdf | Versión final (acceso restringido) | 1,3 MB | Adobe PDF | Abrir Solicitar una copia |
2020_Farias_etal_Langmuir_accepted.pdf | Accepted Manuscript (acceso abierto) | 836,01 kB | Adobe PDF | Abrir Vista previa |
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